Equations (REF ) for the tension \(T\)  are solved at each evaluation of \({u}\) , and this value of tension is used to compute the velocity in an explicit integration scheme with a variable timestep of the Runge-Kutta-Feldberg (fifth order) method. This algorithm, however, is at best \(O(n^3)\)  in the truncation frequency (because the OLS minimizer is \(O(n^3)\) ) and in reality even slower, as more degrees of freedom necessitate a decrease of the time step. For \(n=6\) , our implementation was running at a speed of 40 dimensionless time units per hour for typical values of parameters on one thread of a typical 2.5 GHz processor; for \(n=8\) , the speed decreased to 5 dimensionless time units per hour (giving a very crude estimate for complexity of about \(O(n^7)\) ). This makes investigations of large values of \(n\)  impractical. For our calculations, we choose \(n=6\) . We discuss this choice further in Sec. REF . Most of the simulations were run with the help of GNU Parallel software [1]}.
